<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="保存并发布"/>
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="请选择一级分类"  @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>

        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="请选择二级分类">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.value"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          filterable
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <!-- 课程封面-->
      <el-form-item label="课程封面">
        <el-upload
          class="avatar-uploader"
          :action="BASE_API+'/eduoss/fileoss/uploadOssFile'"
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload">
          <img v-if="courseInfo.cover" :src="courseInfo.cover" class="avatar">
          <i v-else class="el-icon-plus avatar-uploader-icon"></i>
        </el-upload>
      </el-form-item>

      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="addCourseInfo">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import course from '@/api/edu/course'
  import teacher from '@/api/edu/teacher'
  import subject from '@/api/edu/subject'
  import Tinymce from '@/components/Tinymce' //引入富文本编辑器 组件
  export default {
    components: { Tinymce },
    data() {
      return {
        BASE_API: process.env.BASE_API, // 接口API地址
        OSS_PATH: process.env.OSS_PATH,
        saveBtnDisabled : false,
        dialogVisible: false,
        disabled: false,
        courseInfo:{
          title: '',
          subjectId: '',
          subjectParentId:'',
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: 'https://czy-edu.oss-cn-hangzhou.aliyuncs.com/AOTEMAN.jpg',
          price: 0,
        },
        courseId:"", //课程id
        teacherList:[],//讲师列表
        subjectNestedList: [],//一级分类列表
        subSubjectList: []//二级分类列表
      }
    },
    created() {
      this.init();
    },
    //监听
    watch: {
      $route(to, from) { //路由变化方式，路由发生变化，方法就会执行
        this.init()
      }
    },
    methods: {
      init(){
        if (this.$route.params && this.$route.params.id) {
          this.courseId = this.$route.params.id
          this.getCourseInfo();
        }else {
          this.courseInfo={
            title: '',
            subjectId: '',
            subjectParentId:'',
            teacherId: '',
            lessonNum: 0,
            description: '',
            cover: 'https://czy-edu.oss-cn-hangzhou.aliyuncs.com/AOTEMAN.jpg',
            price: 0,
          }
          this.initSubjectList();//初始化一级课程分类
        }
        this.findAllTeacher();//查询所有讲师
      },
      getCourseInfo() {
        course.getCourseInfo(this.courseId)
          .then(response => {
            this.courseInfo = response.data
            subject.getAllSubject()
              .then(response => {
                //获取所有一级分类
                this.subjectNestedList = response.data
                for (let i = 0; i < this.subjectNestedList.length; i++) {
                  let oneSubject = this.subjectNestedList[i];
                  if (this.courseInfo.subjectParentId == oneSubject.id) {
                    //设置二级课程分类
                    this.subSubjectList = oneSubject.children;
                  }
                }
              })
          })
      },
      initSubjectList() {
        subject.getAllSubject()
          .then(response => {
          this.subjectNestedList = response.data
        })
      },
      findAllTeacher(){
        teacher.findAll()
          .then(response=>{
          this.teacherList = response.data
        })
      },
      //一级下拉框触发事件
      subjectLevelOneChanged(value) {
        for (let i = 0; i < this.subjectNestedList.length; i++) {
          if (this.subjectNestedList[i].id === value) {
            this.subSubjectList = this.subjectNestedList[i].children
            this.courseInfo.subjectId = ''
          }
        }
      },
      addCourseInfo(){
        if (this.courseInfo.title == ''){
          this.$message({
            type: 'warning',
            message: '请填写课程标题'
          });
          return
        }
        if (this.courseInfo.subjectId == '' || this.courseInfo.subjectParentId == ''){
          this.$message({
            type: 'warning',
            message: '请选择课程一级分类和二级分类'
          });
          return
        }
        if (this.courseInfo.teacherId == ''){
          this.$message({
            type: 'warning',
            message: '请选择讲师'
          });
          return
        }
        if (this.$route.params && this.$route.params.id){
          course.updateCourseInfo(this.courseInfo)
            .then(response=>{
              this.$message({
                type: 'success',
                message: '修改课程信息成功'
              });
              //跳转到下一步页面
              this.$router.push({ path: '/course/chapter/'+response.data })
            })
        }else{
          course.addCourseInfo(this.courseInfo)
            .then(response=>{
              this.$message({
                type: 'success',
                message: '添加课程信息成功'
              });
              //跳转到下一步页面
              this.$router.push({ path: '/course/chapter/'+response.data })
            })
        }
      },
      handleAvatarSuccess(res, file) {
        this.courseInfo.cover = res.data
      },
      beforeAvatarUpload(file) {
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2
        if (!isJPG) {
          this.$message.error('上传图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      }
    }
  }
</script>

<style scoped>
  .avatar-uploader .el-upload {
    border: 1px dashed #d9d9d9;
    border-radius: 6px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
  }
  .avatar-uploader .el-upload:hover {
    border-color: #409EFF;
  }
  .avatar-uploader-icon {
    font-size: 28px;
    color: #8c939d;
    width: 178px;
    height: 178px;
    line-height: 178px;
    text-align: center;
  }
  .avatar {
    width: 178px;
    height: 178px;
    display: block;
  }
</style>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>

